sangelion: for example, the devel expat stuff can not be checked by ./configure, because ./configure can only check stuff for crostool-NG's host, while we need the expat devel stuff for the toolchai's host, which can be different in case of a canadianc-ross.

sangelion: some of the features ./configure checks for are required, and ./configure will stop. But other stuff is optional, and ./configure warns and continues, and disables appropriate features from the menuconfig.